Corticobulbar tract. And that includes these upper motor neuron axons that are going to innervate lower motor neurons in the brain stem and because the wiring is a little bit more complicated in the brain stem, we can get some different patterns of weakness with abnormalities of this pathway.
Activity theory (AT; Russian: ÑÐµÐ¾ÑÐ¸Ñ Ð´ÐµÑÑÐµÐ»ÑÐ½Ð¾ÑÑÐ¸) is an umbrella term for a line of eclectic social sciences theories and research with its roots in the Soviet psychological activity theory pioneered by Lev Vygotsky, Alexei Leont'ev and Sergei Rubinstein.
Systems theory is the interdisciplinary study of systems. A system is a cohesive conglomeration of interrelated and interdependent parts that is either natural or man-made. Every system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose or nature and expressed in its functioning. In terms of its effects, a system can be more than the sum of its parts if it expresses synergy or emergent behavior. Changing one